Use of alpha lipoic acid as a feed additive for aquatic animals

Abstract

Alpha lipoic acid is employed as a feed additive for aquatic animals including fish and shrimp, especially for cold water fish as for example salmon, bream, bass and for warm water fish as for example carp, tilapia, catfish. More particular, alpha lipoic acid is disclosed herein for the improvement of the feed conversion ratio and/or daily weight gain in fish, for reducing mortality by regulating the micro flora of the gut and/or by protecting the animal against infections caused by pathogenic viruses.

1 . A method of providing an extruded feed pellet for intake by an aquatic animal, wherein the method comprises the steps of:
 (a) forming an aquatic animal feed composition comprised of a powdered mixture of aquatic animal feed ingredients by grinding and/or mixing of at least a carbohydrate source, a protein source, a lipid source, ash, water and optionally one more ingredients selected from the group consisting of fish meal, krill meal, soya concentrate, corn gluten, wheat gluten, pea protein, wheat flour, fish oil, a vitamin, mineral premix, mineral premix plus synthetic phosphorus and combinations thereof,   (b) homogenizing the powdered mixture formed in step (a) until a paste material of the aquatic animal feed composition is formed;   (c) extruding the paste material obtained in step (b) through an extrusion die of an extrusion installation comprising a mold and a number of mixing and kneading zones, comprised of a plurality of alternately forward and backward kneading screw elements;   (d) cutting of the extruded paste material into porous pellets of a suitable length upon exiting the extrusion die;   (e) drying the porous pellets;   (f) coating the porous pellets obtained in step (e) with a coating oil and adsorbing the coating oil into the porous pellet under vacuum;   (g) cooling the pellets to obtain a coated fish feed pellet comprised of the aquatic animal feed composition which is coated with the coating oil.   
     
     
         2 . The method according to  claim 1 , wherein step (f) comprises coating the porous pellets with a coating oil which comprises:
 a carrier oil, and   an alpha-lipoic acid, a salt or derivative thereof as an active ingredient in the form of a powder having a particle size below 1 mm which is embedded in the carrier oil.   
     
     
         3 . The method according to  claim 2 , wherein the carrier oil is at least one oil selected from the group consisting of fish oils, microbial oils and vegetable oils. 
     
     
         4 . The method according to  claim 1 , wherein Use of alpha-lipoic acid, a salt or derivative thereof for the treatment and/or prevention of diseases caused by pathogenic microorganisms or viruses in aquatic animals. 
     
     
         5 . The method according to  claim 1 , wherein step (a) comprises including a fat soluble vitamin in the powdered mixture. 
     
     
         6 . The method according to  claim 5 , wherein the fat soluble vitamin is vitamin E. 
     
     
         7 . The method according to  claim 5 , wherein the fat-soluble vitamin is at least one compound selected from the group consisting of alpha-tocopherol, beta-tocopherol, gamma-tocopherol, delta-tocopherol, alpha-tocotrienol, beta-tocotrienol, gamma-tocotrienol, delta-tocotrienol and esters thereof. 
     
     
         8 . The method according to  claim 1 , wherein the coating oil comprises oleic acid in the range 0.28-229.15 g/kg feed, linoleic acid in the range 0.22-233.24 g/kg feed, alfa-linolenic acid in the range 0.28-225.06 g/kg, arachidonic acid in the range 0.03-24.55 g/kg, eicosapentaenoic acid (EPA, 20:5 n-3) in the range 0.03-73.66 g/kg and docosahexaenoic acid (DHA, 22:6 n-3) in the range 0.03-73.66 g/kg. 
     
     
         9 . The method according to  claim 3 , wherein the vegetable oil is selected from the group consisting of rape seed oil, soy oil and camelina oil. 
     
     
         10 . The method according to  claim 1 , wherein the coating oil is a source of eicosapentaenoic acid (EPA) and/or docosahexaenoic acid (DHA). 
     
     
         11 . A method for reducing mortality in aquatic animals, wherein the method comprises feeding to the aquatic animal a feed comprising alpha-lipoic acid, a salt or derivative thereof. 
     
     
         12 . A method for the treatment and/or prevention of diseases caused by pathogenic microorganisms or viruses in aquatic animals, the method comprises feeding to the aquatic animal a feed comprising alpha-lipoic acid, a salt or derivative thereof. 
     
     
         13 . A composition comprising alpha-lipoic acid, a salt or derivative thereof for use in improving the feed conversion ratio and/or the standard growth rate in aquatic animals. 
     
     
         14 . A composition comprising alpha-lipoic acid, a salt or derivative thereof for use in reducing mortality in aquatic animals. 
     
     
         15 . A composition comprising alpha-lipoic acid, a salt or derivative thereof for use in the treatment and/or prevention of diseases caused by pathogenic microorganisms or viruses in aquatic animals. 
     
     
         16 . The composition according to  claims 15 , wherein the disease is pancreatic disease. 
     
     
         17 . The composition according to  claim 15 , wherein the virus is an alpha virus (SAV), Noda virus (VNN) or white spot syndrome virus (WSSV). 
     
     
         18 . The composition according to  claim 17 , wherein the alpha virus is salmonid alphavirus subtype 3 (SAV-3) virus. 
     
     
         19 . The composition according to  claim 15 , wherein the composition comprises at least 150-1000 mg per kg feed of the alpha-lipoic acid, a salt or derivative thereof. 
     
     
         20 . The composition according to  claim 15 , wherein said composition comprises alpha lipolic acid, a salt or derivative thereof in an amount of at least 150, at least 200, at least 250, at least 300, at least 350, at least 400, at least 450, at least 500, at least 550, at least 600, at least 650, at least 700, at least 750, at least 800, at least 850, at least 900, at least 950 or 1000 mg per kg feed. 
     
     
         21 . The composition according to clam  15 , wherein said composition comprising alpha lipolic acid, a salt or derivative thereof in an amount of 150-1000, 200-1000, 250-1000, 300-1000, 350-1000, 400-1000, 450-1000 500-1000, 550-1000, 600-1000, 650-1000, 700-1000, 750-1000, 800-1000, 850-1000, 900-1000, or 950-1000 mg per kg feed. 
     
     
         22 . The composition according to  claim 15 , wherein said composition is administered to an aquatic animal of the group consisting of salmon, trout, bream, bass and decapod crustacean.